This newly designed lighted nock features two activation methods: External On/Off Switch: Simply push up or down to turn the light on or off. Bowstring Activation: The bowstring compresses a cord in the nock's groove to activate the light. Unlike traditional pin-activated designs, the bowstring compression cord method significantly reduces accidental activation, enhancing battery efficiency and extending battery life. The nock comes with H, S, and GT bushings, making it compatible with arrow shafts that have inner diameters of .204”, .233”, .244”, and .246”.